1. Field of Invention
The present invention relates to an automatic integrated circuit full testing system, apparatus and method. More particularly, the present invention relates to an automatic integrated circuit full testing system, apparatus and method capable of simulating end user's states and performing a dynamic test.
2. Description of Related Art
The rapid progress in computer technologies has brought major changes in our daily lives. Various computer-related products such as servers, workstations, desktop computers, portable computers, personal digital assistant, palm-top PCs, pocket PCs or industrial computers have become an inevitable portion of us in many ways. All these computer products comprise a system of assembled integrated circuits (ICs). Before selling these computer products to the customers, the integrated circuits contained in the computers must be thoroughly tested to ensure their quality.
FIG. 1 is a block diagram showing the schematic architecture of a conventional personal computer (PC). As shown in FIG. 1, major components included in a conventional personal computer 100 are a central processing unit (CPU) 110, a system bus controller 112 and an input/output bus controller 114. A memory unit 116 and an advanced graphic port 118 are electrically connected to the system bus controller 112. A monitor 120 is electrically connected to the advanced graphic port 118 for outputting images. A peripheral component interface (PCI) 122 is connected to the system bus controller 112 and the input/output bus controller 114. An integrated drive electronics (IDE) interface 130, a floppy disk 132, a parallel port 134, a serial port 136 and a universal serial bus (USB) 138 are all electrically connected to the input/output bus controller 114. In addition, an audio unit 140 and an Ethernet interface 142 may also be electrically connected to the input/output bus controller 114.
Each of the aforementioned component units comprises one or more integrated circuits. For example, the central processing unit 110, the system bus controller 112, the input/output bus controller 114, the memory unit 116, the graphic accelerator attached to the advanced graphic port 118, the audio chip as well as the Ethernet chip are all constructed using one or many integrated circuits. Since all these integrated circuits are important electronic elements inside the computer, the functionality of each and the compatibility among these integrated circuit are critical to the smooth operation and the performance of the entire computer system.
FIG. 2 is a flow chart showing the steps for testing an integrated circuit in a conventional method. An initial test of the conventional integrated circuit 202 such as a logic integrated circuit (logic IC) must be conducted at the end of wafer fabrication. After packaging the chip, a final test 204 is carried out before shipment 206. In the final test of an integrated circuit, the integrated circuit is placed inside an automatic test equipment (ATE) such that the contacts on the integrated circuit are electrically connected to the ATE through a test socket. Thereafter, a preset sequence of test steps is carried out to test the functionality thereof. At the end of the test, functionality of the integrated circuit is assessed. Functionality test of the integrated circuit is conventionally carried out using special programs. Furthermore, the final states at the end of the simulation are used to judge the quality of the integrated circuit. According to the test results, the integrated circuits are sorted out in a binning system before shipment.
After conducting a first stage final test 208, integrated circuits such a memory IC must further undergo a burn-in test 210 and a second stage final test 212 before shipment. Both the first stage final test 208 and the second stage final test 212 are carried out using the ATE. Yet, the burn-in test 210 is often performed manually or semi-automatically. The memory IC is plugged into the socket of a test circuit board and then the entire test circuit board with the memory IC is transferred into a heat-testing station that can control the test temperature. Inside the heat-testing station, the memory IC is thermally stressed, voltage stressed or current stressed to test the chip. However, this type of testing only tests the functional aspects of an integrated circuit using simulation programs. The test is not performed in the actual operating environment of an end user. Hence, there still could be an instable or incompatible problem occurred when the integrated circuit is assembled inside a computer after it passes the ATE tests.
FIG. 3 is a flow chart showing the steps in a conventional method of testing an integrated circuit through simulation. Since a conventional testing method does not provide an end-user environment simulation, a circuit module test of the integrated circuit may be conducted after the final test but before shipment. In a conventional module test, a module such as an interface or a test computer is provided. An integrated circuit 302 is manually inserted into the module or the test computer in step 304. The module or the test computer is capable of simulating the operating environment of an end user. Thereafter, the integrated circuit 302 is tested in step 306 and the qualified circuits are shipped in step 308. Because this portion of the testing is mostly carried out manually and quality assessment is also carried out visually, productivity is low and testing time is long. Moreover, quality problems always occur due to human errors, which leads to an increase in production cost and a decrease in testing reliability.
In brief, some of the deficiencies and drawbacks of a conventional testing method include:
1. Since actual test in an end-user environment is not provided, problems such as being compatible to software may still occur even though an integrated circuit has passed the conventional test.
2. The electronic devices are fixedly mounted on the test circuit board for testing an integrated circuit. Hence, compatibility of the same integrated circuit between different devices is untested.
3. The conventional method relies heavily on manual operations and hence severely limits overall throughput and increases the probability of having human errors.
4. The module test method is incapable of providing temperature control for the integrated circuit once the circuit is incorporated into the module. Hence, some of the actual working conditions are not simulated and tested.
5. The integrated circuit is assessed according to the final states and hence incapable of detecting any dynamic errors such as video shaking, discoloring display, ghost shadow or white block produced by a graphic accelerator. Possible conflicts when the integrated circuit executes a particular software program also remain undetected by the conventional testing method.